Time-of-flight mass spectrometers (TOF MS) are widely used in analytical chemistry for identification and quantitative analysis of various mixtures. Sensitivity and resolution of such analysis is an important concern for practical use. To increase resolution of TOF MS, U.S. Pat. No. 4,072,862, incorporated herein by reference, discloses an ion minor for improving time-of-flight focusing in respect to ion energy. To employ TOF MS for continuous ion beams, WO9103071, incorporated herein by reference, discloses a scheme of orthogonal pulsed acceleration (OA). Since resolution of TOF MS scales with the flight path, there have been suggested multi-pass time-of-flight mass spectrometers (M-TOF MS) including multi-reflecting (MR-TOF) and multi-turn (MT-TOF) mass spectrometers. SU1725289, incorporated herein by reference, introduces a folded path MR-TOF MS using two-dimensional gridless and planar ion minors. GB2403063 and U.S. Pat. No. 5,017,780, incorporated herein by reference, disclose a set of periodic lenses for spatial confinement of ion packets within the two-dimensional MR-TOF. WO2007044696, incorporated herein by reference, suggests a scheme with double orthogonal injection for improving OA efficiency. Still, the duty cycle of OA-MR-TOF remains under 1%.
In the co-pending application, PCT Application Number PCT/IB2010/051617, incorporated herein by reference, there is disclosed a cylindrical multi-reflecting electrostatic analyzer, primarily optimized open electrostatic traps, wherein ion beam confinement in the tangential direction is not important.
Summarizing the above, the prior art multi-reflecting TOF systems enhance resolution but limit the duty cycle of pulsed converters. Therefore, there is a need for improving sensitivity and resolution of MR-TOF.